Web services could be harnessed to facilitate the monitoring of resource status, including workload, performance metrics, availability, and capacity, so that policies could be crafted to allocate resources (whether physical, virtual, or cloud-based) to the right I/O. Such an open standards-based resource provisioning model has been embraced by Xiotech and a few other vendors and is on the drawing boards in many product development shops. However, no cloud services companies, including cloud storage startups, have thus far announced support for the strategy.

Asked about standards, most cloud storage providers reference standard certifications such as ISO or various security standards or the name-brand vendor whose storage gear is being used in their infrastructure. These may be standards of a sort, but they're not the kind of standards that promise to become as ubiquitous as TCP/IP, for example.

The absence of real standards for cloud computing generally, and cloud storage specifically, frames the key question that many prospective customers need to ask themselves before embracing the trend: How will I be any better off with clouds over the next few years than I would be from implementing a homegrown strategy of infrastructure right-sizing, improved infrastructure management, and intelligent data management?

The fact is that cloud storage appeals to many companies for the simple reason of cost savings. If vendors can deliver even a percentage of the cost reductions they promise, and if you can feel comfortable that your data will be secure and well managed, then the strategy could be a win-win.

Service-level agreements are very important and may determine the outcome of the cloud experience. An SLA is the vendor's promise regarding the availability and performance of a solution. There's a tendency to set the bar too high when entering into a new outsourcing arrangement, to hold vendors to service levels that would be impossible to deliver under the best of circumstances and regardless of price. Sometimes vendors sign off on impossible-to-meet SLAs just to get the business. When expectations are set too high, however, there's a tendency for the arrangement to sour within a year or two, as the record of traditional outsourcing shows. A clear understanding of both requirements and measurement metrics is important.

Methods for signing up for a cloud service vary from vendor to vendor, as do contract lengths. While some vendors provide a stock SLA and contract, and a few permit sign-up on the Web, most want to meet with a potential client directly to assess the current situation and to arrive at a service offering that's tailored to its needs. In response to our mock request for information, several respondents preferred to go this route.